This week, researchers report the first genetic variant linked to slightly higher risk for severe "dry" age-related macular degeneration, one of the two advanced forms of the disease that robs tens of millions of elderly people of their vision.

The forested western Amazon was once thought barren of complex human culture. But researchers are now uncovering enigmatic earthworks left by large, organized societies that once lived and farmed here.

Facing growing public skepticism, impatient politicians, and a blogosphere rife with conspiracy theories, the Federal Bureau of Investigation (FBI) on Monday sought to bolster its case that Army scientist Bruce Ivins was the perpetrator of the 2001 anthrax attacks by extensively discussing the scientific evidence.

The flat marine organism Trichoplax adhaerens barely qualifies as an animal, yet the 98 million DNA base pairs of its genome include many of the genes responsible for guiding the development of other animals' complex shapes and organs, researchers report this week.